Coal, oil, and natural gas, used by electric utilities and industry to produce energy, have the potential to generate TENORM waste. Wastes from the use of geothermal energy and oil and gas arise primarily from resource extraction. Radioactivity in oil and natural gas is very low and the radioactivity in the wastes produced by their combustion is negligible. TENORM wastes from the use of coal arise primarily from coal ash, in which the naturally-occuring radionuclides in coal are concentrated.